Within the context of petroleum drilling and well completions, wells are typically constructed by drilling the well bore and completing by installing a liner tubular string, referred to as casing or liner.
The liner tubular string is installed either by running it in after the wellbore is drilled or by using the liner tubular string as the drill string to thereby drill the liner string into position. Either way, casing installation through deviated wellbores or by drilling with casing challenges the performance requirements of the casing. Installation can place severe structural demands on casing since they must survive extended periods of time in contact with the borehole wall. Devices, such as centralizers or wear bands can be mounted onto the casing to act as bearing surfaces that preferentially accommodate contact with and space the casing from the borehole wall. However, such devices must be cost effective, since they remain downhole and are not recovered. In addition, these devices must be connected to the casing in such a way that they do not compromise the casing integrity either by their means of attachment or the wear they induce.
In some previous approaches, crimping has been used to secure such devices to the liner string. Welding and setscrews have also been used.